Well, perhaps I should state my points for being sceptic about the sea launch issue;

First; the organizational costs. Sea-based launch and recovery requires about the same number of people and hardware as land launch and recovery, plus the crew for the ships, and obviously the ships themselves.

Second issue is the maintenance. The ships require maintenance, and the sea environment is places quite a heavy burden for electronic components and fine mechanic parts.

Third, the launch platform is unstable unless it's built on an oil rig or similar anchored structure.

There's an old saying about War that amateurs talk tactics while professionals talk logisitics. I wouldn't discount the range & licensing costs. They can and do run into the millions of dollars. In some instances the range & licensing costs can exceed the cost to develop the vehicle. Iagree that there may be increased maintenance and support costs...but then maybe not when veiwed in total. There's a lot of experience, resources, and talent pool available to maintain ships at sea, so the additional costs compared to range & licensing issues may not be significant. Plus they won't be the first:

I think there is a bias towards winged spaceflight because it probably offers the best commercial prospects for human spaceflight and tourism.

One of the most appealing prospects to me about reliable, cheap, regular access to space is the idea of making intercontinental hops in just a few hours. I live in Australia, but my family is in the UK. If I could get to the UK in say 4-5 hours as opposed to 22, I would be prepared to pay quite a bit for it. Especially once prices come down. Now, if you are transporting passengers between continents, it's not terribly elegant to drop them in a capsule, under a canopy, in a field somewhere .

Winged vehicles at least have the prospect of integrating with existing airport infrastructure. Sure, there would have to be some changes, and air traffic control would have to accomodate vehicles dropping rather quickly from the upper atmosphere, but it doesn't require a paradigm shift in the way that passengers are handled, and therefore I think offers the best commerical prospects

Defenitely a good point. Commercial activites will require precision landing capabilities. Thus Starchaser is using a steerable parachute, and Armadillo envisions powered-landings...thus like the DC-X, pinpoint launch to pinpoint landing...something winged aircraft can't do with wings by themselves (think Harrier).

Steerable parachute and vertical tailsitter lander are still ballistic vehicles that can only fine tune their landing area. A winged intercontinental space plane would be able to divert for another airfield if necessary; the capsules will land on the spot where they were aimed at, give or take a few kilometer. Also the winged configuration would be able to utilize already present infrastructure, whereas the rocket design would require purpose-built facilities. Or worse yet, fleet or seaborne vessels at either end.

Steerable parachute and vertical tailsitter lander are still ballistic vehicles that can only fine tune their landing area. A winged intercontinental space plane would be able to divert for another airfield if necessary; the capsules will land on the spot where they were aimed at, give or take a few kilometer. Also the winged configuration would be able to utilize already present infrastructure, whereas the rocket design would require purpose-built facilities. Or worse yet, fleet or seaborne vessels at either end.

Very good points. However, I don't see the SS1 re-connecting with the WK after it fires it's engine. Thus on re-entry, SS1 has limited ballistic options as well...

The scaled.com website states that spaceshipone will be able to glide for 60 miles after re-entry. Also remember that SpaceShipOne is experimental. I think it is a step in the right direction though -- it can't be tooo hard to add powerered landings into a next generation SpaceShipOne. A winged craft seems much more practical for intercontinental hops if the purpose is transportation of people. I think the ability to land at an established airport with all of its facilities is mandatory for commercial viability. I don't think this is absolutetly necessary if the point is space tourism.

Granted, it all depends om what your business model is. Various configurations offer pros & cons depending on the model. The point at the moment, is that there are limitations to all the X-prize vehicles. Starchaser lands as a "glider" just as SS1. There are benefits to pinpoint landing versus runway landing...the same with Sea versus Land launch. I think the open-ended nature of the X-prize, is not to limit ourselves into what is "acceptable." It is highly likely that the future will be different than what most of us today think it may be.

Airports will require modifications for whatever the eventual passenger carrying vehiccle will be. The ability to adapt existing infrastructure to a future vehicle, is trivial compared to the accomplishment of developing the vehicle. I don't think airport infrastructiure savings is the driving rwquirement for the successful model. A powered tail-lander, parasail glider, or traditional winged craft will all be able to land at existing airports.

In short, I think we hope success for all entrants. The diversity of designs helps expand the options for future development.

For research and private ventures, any approach is undeniably welcome. For a desert site a vertical ascent / parachute descent would probably be better than any other. And bringing down any type of craft on an airport poses no technical problems.

However, the hard fact is that current airport and air traffic protocols are intended for airplane-type vehicles. Modifying them to suit ballictic crafts is not trivial by either financially or bureaucratically. A parawing would give the vehicle some maneuvering capability, but would not turn it into an airplane.

For research and private ventures, any approach is undeniably welcome. For a desert site a vertical ascent / parachute descent would probably be better than any other. And bringing down any type of craft on an airport poses no technical problems.

However, the hard fact is that current airport and air traffic protocols are intended for airplane-type vehicles. Modifying them to suit ballictic crafts is not trivial by either financially or bureaucratically. A parawing would give the vehicle some maneuvering capability, but would not turn it into an airplane.

Which cause the same problems with the SS1, dead-stick landing. There's no holding in the pattern, abort, or fly-around capability. Bringing in an SS1 type craft would give it emergency priority just as a parasail craft, or powered tail-lander.

I think the key thing to recognize that commercial passenger applications are at least one generation away from the current craft, and that modifications will need to be made for any of them...SS1 included.

Which cause the same problems with the SS1, dead-stick landing. There's no holding in the pattern, abort, or fly-around capability. Bringing in an SS1 type craft would give it emergency priority just as a parasail craft, or powered tail-lander.

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A valid point.

I think the key thing to recognize that commercial passenger applications are at least one generation away from the current craft, and that modifications will need to be made for any of them...SS1 included.

Indeed, and the modification that SS1 needs to cope with regular air traffic is basically a jet engine. The airplane configuration offers the platform for a practical solution to unexceptional air and ground handling qualities compared to a parawing that would still require special landing clearance because of a ground crew to collect the collapsed sail (which would also make an expedited taxiing an impossibility) or a tail sitter which I really cannot imagine to mix with regular air traffic.

Indeed, and the modification that SS1 needs to cope with regular air traffic is basically a jet engine. The airplane configuration offers the platform for a practical solution to unexceptional air and ground handling qualities compared to a parawing that would still require special landing clearance because of a ground crew to collect the collapsed sail (which would also make an expedited taxiing an impossibility) or a tail sitter which I really cannot imagine to mix with regular air traffic.

Then essentially you have Bristol's Ascender project, and not the SS1. The more expansive the SS1 becomes, the more problematic the issue becomes for the White Knight. While there are commercial advantages/flexibility for wings and non-wings, the fact that Helicopters work within the current Air Traffic system leads me to believe that power tail-lander can also be made to fit within the system. The Harrier illustrates that there is sufficient need and interest for VTOL craft to support multi-million dollar investment.